Refactoring of game features for better management. (#146)

Author: Holt59

src/CMakeLists.txt

@@ -18,6 +18,7 @@ mo2_add_filter(NAME src/interfaces GROUPS
 	iplugindiagnose
 	ipluginfilemapper
 	iplugingame
+	iplugingamefeatures
 	iplugininstaller
 	iplugininstallercustom
 	iplugininstallersimple

src/game_features/bsainvalidation.h

@@ -1,18 +1,17 @@
-#ifndef BSAINVALIDATION_H
-#define BSAINVALIDATION_H
+#ifndef UIBASE_GAMEFEATURES_BSAINVALIDATION_H
+#define UIBASE_GAMEFEATURES_BSAINVALIDATION_H
+
+#include <QString>
+
+#include "./game_feature.h"
 
 namespace MOBase
 {
 class IProfile;
-}
-
-class QString;
 
-class BSAInvalidation
+class BSAInvalidation : public details::GameFeatureCRTP<BSAInvalidation>
 {
 public:
-  virtual ~BSAInvalidation() {}
-
   virtual bool isInvalidationBSA(const QString& bsaName) = 0;
 
   virtual void deactivate(MOBase::IProfile* profile) = 0;
@@ -22,4 +21,6 @@ class BSAInvalidation
   virtual bool prepareProfile(MOBase::IProfile* profile) = 0;
 };
 
+}  // namespace MOBase
+
 #endif  // BSAINVALIDATION_H

src/game_features/dataarchives.h

@@ -1,20 +1,18 @@
-#ifndef DATAARCHIVES
-#define DATAARCHIVES
+#ifndef UIBASE_GAMEFEATURES_DATAARCHIVES_H
+#define UIBASE_GAMEFEATURES_DATAARCHIVES_H
 
 #include <QString>
 #include <QStringList>
 
+#include "./game_feature.h"
+
 namespace MOBase
 {
 class IProfile;
-}
 
-class DataArchives
+class DataArchives : public details::GameFeatureCRTP<DataArchives>
 {
-
 public:
-  virtual ~DataArchives() {}
-
   virtual QStringList vanillaArchives() const = 0;
 
   virtual QStringList archives(const MOBase::IProfile* profile) const = 0;
@@ -32,4 +30,6 @@ class DataArchives
   virtual void removeArchive(MOBase::IProfile* profile, const QString& archiveName) = 0;
 };
 
+}  // namespace MOBase
+
 #endif  // DATAARCHIVES

src/game_features/game_feature.h

@@ -0,0 +1,37 @@
+#ifndef UIBASE_GAMEFEATURES_GAMEFEATURE_H
+#define UIBASE_GAMEFEATURES_GAMEFEATURE_H
+
+#include <typeindex>
+
+namespace MOBase
+{
+
+/**
+ * Empty class that is inherit by all game features.
+ */
+class GameFeature
+{
+public:
+  GameFeature()          = default;
+  virtual ~GameFeature() = 0 {}
+
+  /**
+   * @brief Retrieve the type index of the main game feature this feature extends.
+   */
+  virtual const std::type_info& typeInfo() const = 0;
+};
+
+namespace details
+{
+
+  template <class T>
+  class GameFeatureCRTP : public GameFeature
+  {
+    const std::type_info& typeInfo() const final { return typeid(T); }
+  };
+
+}  // namespace details
+
+}  // namespace MOBase
+
+#endif

src/game_features/gameplugins.h

@@ -1,24 +1,24 @@
-#ifndef GAMEPLUGINS_H
-#define GAMEPLUGINS_H
+#ifndef UIBASE_GAMEFEATURES_GAMEPLUGINS_H
+#define UIBASE_GAMEFEATURES_GAMEPLUGINS_H
 
 #include <QStringList>
 
+#include "./game_feature.h"
+
 namespace MOBase
 {
 class IPluginList;
-}
 
-class GamePlugins
+class GamePlugins : public details::GameFeatureCRTP<GamePlugins>
 {
-
 public:
-  virtual ~GamePlugins() {}
-
   virtual void writePluginLists(const MOBase::IPluginList* pluginList) = 0;
   virtual void readPluginLists(MOBase::IPluginList* pluginList)        = 0;
   virtual QStringList getLoadOrder()                                   = 0;
   virtual bool lightPluginsAreSupported()                              = 0;
   virtual bool overridePluginsAreSupported()                           = 0;
 };
 
+}  // namespace MOBase
+
 #endif  // GAMEPLUGINS_H

src/game_features/igamefeatures.h

@@ -0,0 +1,166 @@
+#ifndef UIBASE_GAMEFEATURES_IGAMEFEATURES_H
+#define UIBASE_GAMEFEATURES_IGAMEFEATURES_H
+
+#include <memory>
+#include <tuple>
+
+#include <QStringList>
+
+#include "game_feature.h"
+
+namespace MOBase
+{
+
+class IPluginGame;
+
+// top-level game features
+class BSAInvalidation;
+class DataArchives;
+class GamePlugins;
+class LocalSavegames;
+class ModDataChecker;
+class ModDataContent;
+class SaveGameInfo;
+class ScriptExtender;
+class UnmanagedMods;
+
+namespace details
+{
+
+  // use pointers in the tuple since are only forward-declaring the features here
+  using BaseGameFeaturesP =
+      std::tuple<BSAInvalidation*, DataArchives*, GamePlugins*, LocalSavegames*,
+                 ModDataChecker*, ModDataContent*, SaveGameInfo*, ScriptExtender*,
+                 UnmanagedMods*>;
+
+}  // namespace details
+
+// simple concept that only restricting template function that should take a game
+// feature to actually viable game feature types
+//
+template <class T>
+concept BaseGameFeature = requires(T) {
+  {
+    std::get<T*>(std::declval<details::BaseGameFeaturesP>())
+  } -> std::convertible_to<T*>;
+};
+
+/**
+ * @brief Interface to game features.
+ *
+ */
+class IGameFeatures
+{
+public:
+  /**
+   * @brief Register game feature for the specified game.
+   *
+   * This method register a game feature to combine or replace the same feature provided
+   * by the game. Some features are merged (e.g., ModDataContent, ModDataChecker), while
+   * other override previous features (e.g., SaveGameInfo).
+   *
+   * For features that can be combined, the priority argument indicates the order of
+   * priority (e.g., the order of the checks for ModDataChecker). For other features,
+   * the feature with the highest priority will be used. The features provided by the
+   * game plugin itself always have lowest priority.
+   *
+   * The feature is associated to the plugin that registers it, if the plugin is
+   * disabled, the feature will not be available.
+   *
+   * This function will return True if the feature was registered, even if the feature
+   * is not used du to its low priority.
+   *
+   * @param games Names of the game to enable the feature for.
+   * @param feature Game feature to register.
+   * @param priority Priority of the game feature. If the plugin registering the feature
+   * is a game plugin, this parameter is ignored.
+   * @param replace If true, remove features of the same kind registered by the current
+   * plugin, otherwise add the feature alongside existing ones.
+   *
+   * @return true if the game feature was properly registered, false otherwise.
+   */
+  virtual bool registerFeature(QStringList const& games,
+                               std::shared_ptr<GameFeature> feature, int priority,
+                               bool replace = false) = 0;
+
+  /**
+   * @brief Register game feature for the specified game.
+   *
+   * See first overload for more details.
+   *
+   * @param game Game to enable the feature for.
+   * @param feature Game feature to register.
+   * @param priority Priority of the game feature.
+   * @param replace If true, remove features of the same kind registered by the current
+   * plugin, otherwise add the feature alongside existing ones.
+   *
+   * @return true if the game feature was properly registered, false otherwise.
+   */
+  virtual bool registerFeature(IPluginGame* game, std::shared_ptr<GameFeature> feature,
+                               int priority, bool replace = false) = 0;
+
+  /**
+   * @brief Register game feature for all games.
+   *
+   * See first overload for more details.
+   *
+   * @param feature Game feature to register.
+   * @param priority Priority of the game feature.
+   * @param replace If true, remove features of the same kind registered by the current
+   * plugin, otherwise add the feature alongside existing ones.
+   *
+   * @return true if the game feature was properly registered, false otherwise.
+   */
+  virtual bool registerFeature(std::shared_ptr<GameFeature> feature, int priority,
+                               bool replace = false) = 0;
+
+  /**
+   * @brief Unregister the given game feature.
+   *
+   * This function is safe to use even if the feature was not registered before.
+   *
+   * @param feature Feature to unregister.
+   */
+  virtual bool unregisterFeature(std::shared_ptr<GameFeature> feature) = 0;
+
+  /**
+   * @brief Unregister all features of the given type registered by the calling plugin.
+   *
+   * This function is safe to use even if the plugin has no feature of the given type
+   * register.
+   *
+   * @return the number of features unregistered.
+   *
+   * @tparam Feature Type of game feature to remove.
+   */
+  template <BaseGameFeature Feature>
+  int unregisterFeatures()
+  {
+    return unregisterFeaturesImpl(typeid(Feature));
+  }
+
+  /**
+   * Retrieve the given game feature, if one exists.
+   *
+   * @return the feature of the given type, if one exists, otherwise a null pointer.
+   */
+  template <BaseGameFeature T>
+  std::shared_ptr<T> gameFeature() const
+  {
+    // gameFeatureImpl ensure that the returned pointer is of the right type (or
+    // nullptr), so reinterpret_cast should be fine here
+    return std::dynamic_pointer_cast<T>(gameFeatureImpl(typeid(T)));
+  }
+
+public:
+  virtual ~IGameFeatures() = default;
+
+protected:
+  virtual std::shared_ptr<GameFeature>
+  gameFeatureImpl(std::type_info const& info) const              = 0;
+  virtual int unregisterFeaturesImpl(std::type_info const& info) = 0;
+};
+
+}  // namespace MOBase
+
+#endif

src/game_features/localsavegames.h

@@ -1,23 +1,21 @@
-#ifndef LOCALSAVEGAMES_H
-#define LOCALSAVEGAMES_H
+#ifndef UIBASE_GAMEFEATURES_LOCALSAVEGAMES_H
+#define UIBASE_GAMEFEATURES_LOCALSAVEGAMES_H
 
 #include <QDir>
 
+#include "./game_feature.h"
 #include "filemapping.h"
 
 namespace MOBase
 {
 class IProfile;
-}
 
-class LocalSavegames
+class LocalSavegames : public details::GameFeatureCRTP<LocalSavegames>
 {
-
 public:
-  virtual ~LocalSavegames() {}
-
   virtual MappingType mappings(const QDir& profileSaveDir) const = 0;
   virtual bool prepareProfile(MOBase::IProfile* profile)         = 0;
 };
+}  // namespace MOBase
 
 #endif  // LOCALSAVEGAMES_H

src/game_features/moddatachecker.h

@@ -1,14 +1,15 @@
-#ifndef MODDATACHECKER_H
-#define MODDATACHECKER_H
+#ifndef UIBASE_GAMEFEATURES_MODDATACHECKER_H
+#define UIBASE_GAMEFEATURES_MODDATACHECKER_H
 
 #include <memory>
 
+#include "./game_feature.h"
+
 namespace MOBase
 {
 class IFileTree;
-}
 
-class ModDataChecker
+class ModDataChecker : public details::GameFeatureCRTP<ModDataChecker>
 {
 public:
   /**
@@ -59,12 +60,7 @@ class ModDataChecker
   {
     return nullptr;
   }
-
-public:
-  /**
-   *
-   */
-  virtual ~ModDataChecker() {}
 };
+}  // namespace MOBase
 
 #endif